1. Technical Field of the Invention
The present invention relates to a direct drive motor wherein a rotary shaft of a rotor is directly connected with a body to be driven such as a turn table. More particularly, the present invention relates to improvements in the mounting structure of a stator used in the direct drive motor.
2. Background of the Related Art
A disk driver for rotating a disk such as a floppy disk, which will be referred to as FD hereinafter, includes a turn table for rotating FD, and a motor which is a drive source to drive the turn table. The mainstream of the motor used for the above object is a direct drive motor in which a rotary shaft of the rotor is directly connected with the turn table.
FIG. 3 is a partially cross-sectional view of direct drive motor used for a conventional disk driver. In the drawing, reference numeral 1 is an annular stator. In this stator 1, there are provided a plurality of cores 2 which are laminated on each other, and magnetic poles are formed like a spur gear in the plurality of cores 2. A winding wires 3 are provided about the magnetic pole section 10 of the stator 1. At the center of the stator 1, there is provided a mounting section 20. This mounting section 20 is fixed to a step portion of the support section (a bearing or a housing) 4 by screws 5. Reference numeral 6 is a printed board, which is fixed to a main frame (not shown).
At the center of the bearing 4, there is formed a through-hole 7, into which a rotary shaft (not shown) is inserted, and this rotary shaft directly connects a rotor (not shown) opposed to an upper portion of the stator 1, with a turn table (not shown) opposed to a lower portion of the printed board 6.
In order to reduce the size of an apparatus into which this type disk driver is incorporated, there is a requirement of decreasing the thickness of the disk driver. However, according to the conventional mounting structure shown in FIG. 3, head portions of the fixing screws 5 are protruding from an upper surface of the laminated core 2. Therefore, it is difficult for the stator and rotor to be arranged so close to each other. For the above reasons, it is impossible to decrease the thickness of the disk driver.